Wednesday, March 23, 2011

On Bags of Holding


Observation: Bags of holding are really a rules hack to patch over the broken D&D economy system.

D&D Basic Economy Bug #1 -- D&D set its price list in units of "gold pieces" (OD&D Vol-1 p. 14, etc.). Historically this is incorrect; basic items would really be bought with silver coins. So, broadly speaking, the indicated prices are about ×10 too high.

D&D Basic Economy Bug #2 -- D&D set the encumbrance for its "gold piece" at 1/10 of a pound weight (OD&D Vol-1, p. 15, etc.). Historically, this is also incorrect; actual coins have always been much smaller. So, broadly speaking, the coins here are about ×10 too large/heavy.

Putting these together, the value of carryable treasure (in terms of purchasing power) is only about 1/100th what it "ought" to be. If you carry from the dungeon a back-breaking, seam-splitting sack full of silver (say 100 pounds) then in D&D you can buy, say, 25 gallons of wine with that; while in reality it should be more like 30,000 gallons. If the sack is full of gold, then you can buy 30 draft horses in D&D; when in reality, it should be more like 2,000 such horses. Stuff like that. (See here for documentation on real medieval pricing.)

So, bags of holding are really a necessary fix to let adventurers carry out enough treasure that they can actually do something useful with it (buy a ship, build a castle, outfit an army -- or gain a level). And they're one of the most universally recognized D&D magic items because every PC adventuring party basically needs one.

(This has been mentioned in passing in prior blogs on D&D money.)

35 comments:

  1. Thanks for explaining why the Bag of Holding feels like a bad patch! I feel like the gold standard is too tough a nut to crack, so what do you think about lowering all prices?

    ReplyDelete
  2. Yes. But then, the whole implicit economy in D&D is broken so thoroughly that I've never been able to formulate a sensible post about it. Even if one translates "silver piece" to "pig iron," the relationships between commodity prices present a totally unfamiliar world. And then the advantages of, say, plate mail vs. a +2 magic sword make it very hard to know what to think of the specialness of magic in the implied setting.

    C'est un bazaar.

    ReplyDelete
  3. To me they are actually there as some kind of bad hack invented by a monty haulish DM to allow a player not to be picky with the kind of treasure collected. This allows to simply pick up every shiny thing in the dungeon, solution that is not doable with normal encumbrance rules, as the amount of coins found rises very soon, but the relative experience density of treasure drops exponentially. While I'm exploring without a bag of holding I have to choose whether to explore a bit more to gain "denser" treasure such as gems and art objects or instead settle with about 2000 coins in stupid coinage.

    With a bag not only there is no encumbrance, but also the amount of gold and experience that can be extracted is not capped, thus the diminishing return caused from the going back and forth from base to the dungeon to cash money and xp is much, much more limited as it can happen much less often.

    ReplyDelete
  4. Also I think i just won the prizes for "most subordinate phrases in a sentence" and "most convolute thoughts" :D

    ReplyDelete
  5. You see a hack, I see an opportunity to make bags of holding something more alive, more capricious, more fey, more not just a big bag...

    Time for a table...

    ReplyDelete
  6. "experience density of treasure" deserves a post all by itself. Thank you.

    ReplyDelete
  7. Hey, Jeff -- Honestly, I do just fix those two "bugs" directly in my game. First, interpret the price list(s) as being in silver, not gold (lowering prices, as you say). Second, rescale weight to about 100 coins per pound (specifically 1,000 per stone).

    More here: http://deltasdnd.blogspot.com/2010/05/money-results.html

    ReplyDelete
  8. richard said: "Even if one translates 'silver piece' to 'pig iron,' the relationships between commodity prices present a totally unfamiliar world."

    This I would differ with. I've found that if you convert OD&D prices to silver pieces, and interpret "silver piece" as a real-world Groat (4 pence; 1/3 shilling), then the prices and relationships are generally pretty accurate. See a bunch of examples we've tried in the link immediately above (also in comments there).

    ReplyDelete
  9. Hi, ChicagoWiz -- I'm not arguing that a rules hack can't also be a creative opportunity. A "happy little accident" as Bob Ross would say. :)

    ReplyDelete
  10. my big pricing problems have always been with metal armour and warhorses - though as Jovial Priest observed in January (sorry no links - on phone) plate mail price changed over the editions. I'm with Richard II - no man is worth a whole horse.

    For my own game I abandon history in favour of preferred outcomes: swords and metal armour are for nobles only. your 1st level adventurers use leather and spears.

    ReplyDelete
  11. I've tried to work with those sources on medieval prices but there's a lot of variance on basic things like a chainmail shirt. I guess they were very expensive to make but are cheaper in areas where a lot are in "circulation" (say, where their wearers get killed off...)

    Currently I use silver standard, 500 coins make a weight, about 8 weights before you start moving slower (less you have armor on already).

    ReplyDelete
  12. I've generally thought of bags of holding as being one of many items and abilities in D&D that basically say, "Well, that gameplay was interesting but we're done with it now and we're going to move onto something new and interesting."

    The timing on this post was very synchronistic for me, though. I was just dropping by to point you in the direction of the week-long series I just started extrapolating your encumbrance by stone system.

    @tsojcanth: Bags of holding aren't entirely without weight. I've seen players pass up on a type III bag in favor of a type I bag because it would screw up their encumbrance to carry the heavier version.

    ReplyDelete
  13. richard said... "my big pricing problems have always been with metal armour and warhorses"

    You got me there. The one undeniably glaring wrongness is that the armor's too cheap (relatively speaking). And also mercenaries. Everything else works out pretty well when I check it.

    ReplyDelete
  14. Justin: Ridiculously cool! Thanks for the link and the shout-out. :)

    ReplyDelete
  15. tsojcanth said...
    "To me they are actually there as some kind of bad hack invented by a monty haulish DM to allow a player not to be picky with the kind of treasure collected. This allows to simply pick up every shiny thing in the dungeon, solution that is not doable with normal encumbrance rules, as the amount of coins found rises very soon, but the relative experience density of treasure drops exponentially. While I'm exploring without a bag of holding I have to choose whether to explore a bit more to gain "denser" treasure such as gems and art objects or instead settle with about 2000 coins in stupid coinage."

    That's so backwards, though. The point of coinage made from precious metals is to have a high value-weight ratio. Coins and gems should never be poor choices when it comes to getting the most out of your encumbrance limit. If you just switch the relationship, and make the inefficient treasure the miscellaneous mundane stuff (artworks, furniture, fabrics, furs, looted armor, etc.) and the efficient treasure the coins and gems, then you can still have the gameplay element of having to choose which treasure to haul away, without the absurdity of coins being relatively encumbering for their value.

    ReplyDelete
  16. I wouldn't go so far as to say that the Bag of Holding was created as a rules hack so much as it has obviously been used as one. It seems like the ideal kind of magic item on the surface: it has a unique power, it can't be boiled down to mathematical adjustment, and it comes straight out of existing media (well... Tex Avery). Does anyone know what edition it first appeared in?

    ReplyDelete
  17. Jason Withrow said: "Does anyone know what edition it first appeared in?"

    It's been there since the beginning -- OD&D Vol-2 p. 38.

    ReplyDelete
  18. While I like the idea of coins being a fairly convenient way to carry a lot of wealth (small, relatively lightweight coins of relatively high value), I do have one problem with it: dragon hoards.

    I want my dragons to sleep on a giant pile of gold and silver, and if you increase the value-to-weight ratio by huge amounts, you're severely increasing the amount of purchasing power your PCs have after slaughtering a dragon. Either that, or your dragons have a "hoard" that can fit in your backpack.

    I generally don't hand out bags of holding, either, for the record.

    ReplyDelete
  19. spartakos said: "I want my dragons to sleep on a giant pile of gold and silver, and if you increase the value-to-weight ratio by huge amounts, you're severely increasing the amount of purchasing power your PCs have after slaughtering a dragon."

    I can see that as a legitimate concern.

    ReplyDelete
  20. On the last point, here's some idle calculations (everyone else ignore this if you want). In my revised system, coins are about 1/100 pound, and coin treasures reduced by 1/10 (so as to balance against increased value).

    Average OED dragon treasure is therefore 1,800 cp; 5,000 sp; 3,500 gp. In pound weight that's approximately 18# cp, 50# sp, 35# gp (total 103 pounds). Dividing by density of each metal, that's bullion cubic feet of 0.03 cp, 0.08 sp, 0.03 gp (total 0.14 cubic feet, i.e., close to 1 gallon). So spartakos is right, it looks like a strong man with a strong container could haul that away.

    Say average OD&D dragon is about 10 feet long (I like HD~feet length like in 3E for a lot of reasons). Maybe sleeping he curls up into a 5x5 foot space (area 5x5=25 square feet). Say we double bullion volume to represent loose coin packing (0.14x2 = 0.278 cubic feet). Divide by square footage under dragon (0.278 ft^3 /25 ft^2 = 0.0112 feet x 12 inches/foot = 0.13"). And that the thickness of about 2 U.S. quarters. So in this case you'd have a thin sheet of highly valuable coinage under a dungeon-dwelling D&D dragon. (Quickly done, could have errors; no warranty of fitness for a particular purpose implied.)

    "Normal" hyper-inflated and super-heavy (big) D&D coinage you'd multiply that by about 100, i.e., 13" or about one foot deep. Or reduce that if you think you've got larger-sized dragons.

    ReplyDelete
  21. I really don’t see bags of holding as a “hack” or “bad patch”, I see it as a tool to ease gameplay.

    The party slays a dragon in its mountain lair. Great! Now they have a treasure hoard! (Realistic currency system or not, dragons etc. should have a LOT of treasure.) Now all they have to do is go down the mountain, trek through the wilderness for days if not weeks having random encounters (for a while, dragons or their ilk are typically remote), hire a train of horses, wagons, teamsters etc., trek all the way back (more encounters), haul the treasure from the mountain to the wagons, more trekking (more encounters), and finally back into town before they can spend their new shiny loot.

    Now, this level of realism I’m sure is sought by some gaming groups, but I’d say a –lot- of players would much rather sweep the hoard up into their bags of holding, get back to town and spend their booty, and get on with some more adventures instead of back-and-forth busywork. The bag of holding allows a victory to be celebrated and be moved on from, not turned into a chore for the players.

    At low levels, the bag of holding isn’t relevant- fewer magic items (if any) and less loot, its there so that when the levels climb and the treasure with it, that the party isn’t bogged down and the game can move on more quickly.

    ReplyDelete
  22. Dusk -- Just to be clear, at no point did I use the word "bad" in the post, eh?

    Now, my standpoint from 2 comments up is that if you just make coin realistic size & value, you can carry away the whole dragon hoard worth in a conventional backpack. Of course, some other people (see above) do like a "Hobbit" inspired enormity that triggers armies feuding over the hoard.

    I agree with you, though (prefer to avoid that) -- and as usual it seems like the most straightforward fix is to just match reality regarding that point.

    ReplyDelete
  23. Thanks for those calculations Delta.

    I am cool with not having enormous dragon hoards. But perhaps it is because my favourite version of basic D&D, the one with the Otus cover, is the one with the realistic looking treasure, rather than the other two with the swimming pool-sized hoards.

    Incidentally, it seems to me that this is the reason gold coins are the standard currency in D&D, rather than silver. Gold coins at 10 to the pound are just barely plausible, about the size of a silver dollar iirc. A silver coin weighing 1/10 of a pound would then be almost double that size. Better to spend as little time as possible playing around with silver coins.

    ReplyDelete
  24. @Delta, previous comments had been more negative than the original post, I was in part responding to them as well.

    Sure, lightening the load will help a lot too- I've kept the gold standard of currency (its a fantasy world so i'm not bothered by gold being so prolific, its arbitrary either way) but I've reduced coin weights to 1/100th of a pound instead of the original 1/10th.

    In reference to people worried about "purchasing power" of rich PCs- what are they buying with it? If Magic Items of any sort are even on sale, they should be both rare and ridiculously expensive (bear in mind it costs a magic user 250gp to make a single healing potion), and if they're not then the PCs should be saving up for that castle/monastery/wizard tower! If they don't care for the "end game" then have them travel to exotic locales and force them to buy their own ship/airship and fund whole expeditions! (After all, remote and dangerous places can't all have chartered ferries, right?)

    ReplyDelete
  25. So in a silver system, do you change the value of treasure found, or just the cost of purchasing items? I noted recently that in the B/X books the dungeon stocking rules note that unguarded treasure ALWAYS contains silver pieces, which I find intriguing, but don't really get. At any rate would these stay as SP or do you turn them into CP in a silver economy.

    ReplyDelete
  26. Hey SOE -- In theory you could do either. Personally I divide coin treasure quantities by 10 -- what used to be 1,000's of sp is now 100's of sp, etc. That gives a x100 boost to carryable value, whereas if you downgrade coin types (sp->cp) you only get the x10 boost from decreasing weight (if you do that).

    The B/X books table is the same as in OD&D (Vol-3, p. 7). The other reason I don't want to downgrade coin types is because then there would never be any gold!

    ReplyDelete
  27. And link to where I first presented that (item number 2).

    ReplyDelete
  28. Ick, correction on dragon treasure calculation above: I'm supposed to do creature length as about HDx2. So double dragon length above (~20 feet), quadruple sleeping area and reduce thickness of pile to 1/4 shown above (unless your dragon is very serpent-like and curls up into a tighter ball).

    ReplyDelete
  29. Interesting because my complaint about the D&D economy being broken is a bit different.

    In OD&D and AD&D1 with the principle source of xp being gold by fourth level most characters have no reason to adventure. A fourth level fighter will have found in the neighborhood of 6,000 gp or more. Given plate mail is all of 60gp, a good sword 10, and a week's rations 5 he's got food for twenty years and the best armor and weapon out there.

    I'm much more inclined to leave prices in gold and award xp for silver then scale back treasures. Being a lord should mean something in terms of "now I can afford nice stuff".

    ReplyDelete
  30. Although they can can vary quite a bit, if you look at very old coins in European museums they are usually the diameter of a dime but thinner. If you are willing to assume for gaming purposes that all coins have approximately the same weight and size it simplifies matters. Using the thin dime assumption you could assign coins to weigh 1/200 lb or 200 coins = 1 lb. play with dimes and some small containers and you can come to the conclusion loose coins occupy space equal to 25 per cubic inch.

    Conveniently these are numbers which do not strain credibility too much, and allow simple math. :-)

    It has worked for me for many years. The switch from gold to silver standard is a much harder change to make. I wish I had done it years ago. With a long running campaign world it is difficult to switch now.

    Cheers

    ReplyDelete
  31. Barad, you're right and I think that's fine for smaller coinage -- I might assume the same thing for the cp in my campaign. For sp I assume something bigger, like a Groat (around 90 grains = 0.0129 pounds, i.e., 78 per pound, about 1000 per stone).

    http://en.wikipedia.org/wiki/Groat_(coin)

    ReplyDelete
  32. I realize this post has more to do with economics, but I'm surprised no one mentioned how absurdly small the containment density of a Bag of Holding is. The smallest bags (250 lbs/30 cubic feet as described in the 1979 DMG) have the highest density, about 0.133 grams/cc. The largest bags hold less than 0.1 grams/cc. Not only could you not fill them with gold coins, you couldn't fill one with cotton without it rupturing!

    Granted, the largest bags can hold 1500 lbs, 250 cubic feet. On the one hand, filling that volume with solid gold would equate to over 3 million gp at the original 10 gp/pound. And 15000 gp is a lot in any case. But that would only take up maybe 2 - 3 cubic feet. What are you supposed to do with all that extra space?!

    A friend and I realized a long time ago that Bags of Holding were decent for carrying really bulky things so long as they didn't weigh too much (like a rigid suit of armor), but for hauling dense treasure you really need something else. We came up with the "Purse of Lightness". The volume inside is the same as any normal bag, but it makes anything you put into it 10/20/50 times lighter - kind of like a permanent levitation spell inside the bag (which we figured would be exactly how a wizard would go about creating one). The other nice thing about one of these was that it wasn't as big as a large backpack, more like a small tote bag, which makes you substantially less conspicuous when walking around town with 1000s of gp.

    As for dragon hoards, value isn't the only problem. There's also just the sheer number of coins. Even a relatively small mound, say about 8 feet across and 4 feet high, will have literally millions of coins. Either your dragon has managed to hoard a very large fraction of all the coins minted in the region, or the local sovereign is minting coins on a truly industrial scale. The only solution I ever came up with was to keep the outside volume big, but take out a big chunk of the interior with something like a rock (boring), a few dead bodies (sort of interesting, if a bit gross), or a giant spider's nest (surprise!).

    ReplyDelete
  33. Just reread my comment and realized I forgot to mention this. I converted the containment density to g/cc for easy reference to gold density, which is about 19.3 g/cc. In other words, if you fill a Bag of Holding to its weight limit with gold, it takes up less than 0.5% of its rated volume.

    ReplyDelete
  34. Rufus, great observations all around. I never would've noticed the density issue in the bag of holding.

    Also, a friend pointed out a Forbes article this week that does a very similar calculation on the value of Smaug's treasure pile (8.6 billion USD if dragon 20' nose to ass).

    http://blogs.forbes.com/michaelnoer/2011/04/06/how-much-is-smaug-tolkei-dragon-worth/

    ReplyDelete
  35. Spawn of Endra: unguarded treasure contains silver and copper because the adventurers who killed the guardian before you got there took the good loot and left the small change, which is what most parties would do.

    Rufus: Portable Holes have a volume limit but no weight limit. There was an in-depth Dragon article about it early on, which ended up with something like 4 coins per cubic inch if loose and 5 coins per cubic inch if carefully stacked. Something like that.

    ReplyDelete